Code-call system



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O. BLYHOLDER coD-CALL SYSTEM Aug. 9, 1949.

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O. BLYHOLDER Aug. 9, 1949.

CODE-CALL SYSTEM H FW... m/ W U10 n/ M 2,7m No E T 4x5 .Z 2 I S MH C x x N.

m V m N m W Original Filed Jan. 24, 1944 Patented ug. 9, 194

Orlando Blyholder, Chicago,

logg Switchboard and Supply Company, Chicago, Ill., a corporation of Illinois Original application January 24, 1944, Serial-No. 519,550, now Patent No. 2,442,947, June 8, 1948. .Y Divided and this application January 19, 1946,

Serial No. 642,413

This application is a division of my application for `Code-call systems, Serial No. 519,550, filed January.24,V 1944, now U. S, Patent 2,442,947, dated June 8, 1948. n e,

This invention relates to code-'call systems such as are used in industrial establishments, 'or the like, to page designated persons who may be away from their desks, oflices, or stations.

GENERAL DESCRIPTION Y v In a code-call System of the type .underconsideration, a register-sender transmits impulses, over a common signalling line 'to-appropriately located signalling devices, according.A to preassigned code numbers. Y

The main object of vision of a code-call system ofthe general'type outlined above which is reliable in operation and economical t-o manufacture. i

' A specific object of the invention is to provide a code-call system of the foregoing type in Which the register-sender transmits code numbers con` taining a variable number ofcode digits, each of which has a variable value, in which the interdigit spacing is independent of the number of. V'iinpulses inthe concerned digits, and in which the internurnber spacing is independent Yof the num-` ber of digits and the respective values thereof.

A further specic object isv to provide a code'- call system of the foregoing type in which the 1 register-sender comprises a group of suitably interconnected relays. 1 f' f A still further specic object is 'to provide a system in which a number of control stations may be used without mutual interference.

Features ofthe invention are that (l) anim'- pulse counter (consisting of a group of counting relays) Ycounts the impulses of any transmitted digit, beingrused over and over for this purpose; (2) a digitcounter (a group of relays) is' controlled by the impulse counter to count the transmitted digits, associating the impulse counter each time with the next successive register portion; (3)A the impulse counter introduces a uni'- the invention is thepro.-

3 Claims. (C1. 177;-353) watchman or 'other person orlnthevprejmises of the location of an entrance at which Va'pu'sh but-rl ton has been actuated.

A special feature of the invention is thatfthe relays of thel impulse counterl comprise only those necessary tothe Yimpul'se-counting operationjand the relays'oi the digit counter'comprise only those necessary to `the digit-counting operation, the counting relays of these devices performing all switching operations Anecessary to secure the transmission loffthefrecorded number `of digits ofthe respective values recorded.

A further special'feature lis that,`while the'termination of thenumber-transmitting operation is under the control of the operator, the terminatingpact, wheneverperformed,y is automatically nullied until any numberv beinggcurrently trans.- mitted has beenv fully transmitted, .whereby the act of termination does not yabbreviate such nume ber.'

Other objectsand features of theinventionwill become more apparent upon aI further perusal of the specification-in connection with the accom,- panying drawings, comprising-Figs. 1 to 5.

-Fig. 1, partsl to 3, shows a first embodiment of the invention, wherein non-locking control keysare provided and the key operations are registered on relays; i; 1

Fig..2, partsl andZ, shows a second embodiment of the invention, whereinilocking-type control keysare employed., renderingthe use .of register relays unnecessary,- andY wherein modified circuit arrangements are employed to control .the impulse counter; V I l Fig. 3 shows a modification of the registerportion of Fig.` 2, the locking key set being replaced by .a telephone typecalling device and suitable registers; I y Fig..4 is a chart givingv the time of operation andrelease of the'lcounting relaysiof the vimpulse and, digit counters of Fig. .1 withjrespect to generated and transmitted-impulses;

Fig 5 shows how vthe, sheets4 on which Fig. 1

are drawn should be assembled; and- Fig. 6 shows howthe sheets on whichrFig. 2 aredrawn shouldbe assembled@ APPARA'rUs or Fciiiza'fl The apparatus of Fig. '1` includes aV key setil vlustrated diagrammatically at= KS In and* a duplimate-keysetindicated by the rectangle at KS2. Key set'KSl` includesa signal lamp l I6 andi sev@ eral non-locking keys, or push buttons. V*These keysv include start key S, release key R, andA three sets of digit keys H3 to` H5. This key set is 3 interconnected with the remaining equipment of the system by conductors which may be in cable form, as indicated at II'I for the interconnection with the duplicate key set KS2.

The recording relays KI to KIS areV associated respectively with the fteen digit keys of either Y key set.

Chain-Control relay CC is common to the two* key sets, and is interconnected with chainfrelays CI and C2, individual respectively to the key sets KSI and KS2. For each additienalkeyflsetde- D4, interconnected to serve as a digit counters' and repeating relay RR, which repeats impulses to the common signalling line having signal de.- vices such as SD connected thereto. L

Relays I to 5, part 3 of Figyl, comprise the entrance group. Each relay may be associated with a different entrance at which there is an outi sidestart push button suchA as I2I to be controlled by the visitor andan inside stop button |22 to becontrolled by the person admitting the vis'itoruf y The equipment in `the upper left-hand corner of Figyl, part 1, is alarm control equipment, comprising contact, signal, and relay devices to I 06.

V.APPARATUS 0F FIGURE 2 The apparatus of Fig. 2 includes a key set illustrated diagrammatically at KSI, and a duplicate key set indicated at KS2. Key set KS I includes a signal lamp 2I6, non-lockingstart and release keys S and R', and three sets oi locking digit keys.2|3 to 2|5. Since the Ydigit keys of KSI' aref-of the locking type, they may be used to retain the record of the digit information set up thereon/whereby recording relays similar to KI to K|5 of Fig. 1 are not necessary in the arrangement-of Fig. 2. Y

' RelaysV CC', CI', and C2 are similarv in function to the corresponding relays of Fig. 2.

The relays shown above the broken line 3;-3

extending across part 1 of Fig. 2 correspond vrin function to the similarly designated relays of Fig. 1, except for modicatons which will be brought out inthe detailed description to` follow.

APPARATUS oF FIGURE 3 Fig. 3 shows a modification of the of Fig. 2 shown below broken line 3 -3 across part 1 thereof.

In Fig. 3, key sets KSI' and KS2' are replaced by the control stations illustrated diagrammatically at CSI, andthe similar station indicated at CS2. The equipment at control station CSI `includes the calling device CD, which may be a sender of the dial-controlled type commonly used at'iiautomatic telephone Asubstations.Y The nonlocking start and release keys R2 rand S2 cor-- respond respectively to the keys R and S of Fig. 2; and the signal lamp 3|6 corresponds to the lamp 2I6 of Fig. 2.

Relays CC2, CI2.' and C22 correspond respectivelyin general function to relay CC', CI', and

apparatus extending mitted from either controlstation. Registers RI n key sets.

to R3 are provided to record such trains of impulses. Each such register may comprise a magnetic impulse counter of the type illustrated in Figs. 21 to 25 of the co-pending application of Jolin IJBellamy,'fSerlalfNo'.` 493,312, led July 2, 1943, now U. "S. Patent-2,441,001, dated May 4, 1948.

`V `vv`lRelays IMP, TRI, and TR2 comprise an im- -Ypulse-'relay and two transfer relays interposed betweenthe calling device of a connected one of theYcontrolistationsnand the registers RI to R3,

for control purposes, to be later described.

DETAIpED DESCRIPTION i4 FIGURE 1 IA. Calling No. 555

AM detailed description of the operation of the system as shown in Fig, 1 will now be given. For this purpose, it will be assumed that the operator at key set KSI desires to transmit call No. 555, being a call numberhaving the maximum number of digits (3) each `digit being represented by the maximum number of impulses` (5).

`vLAI. INDIVIDUALIZING THE SYSTEM'WITH KEY SET Ksl j The system must first be individualized with the key set, KS To lthis end, the start key S is actuated and held until lamp I I6 lights as a signal that the `system hasA become individualized as desired. TWhen the system is not in use, the'ungrounded pole0 of `thefcommon current source is connected through the lower contacts of start relay ST, guard conductor I0'I`,`and'contacts' of' chaincontrol relay CC, to conductor I50,.Whereby actuationV of start key'S `(whose movable vcontactis grounded) energizes the lower winding of chain relay HCI. n 'Relay-CI thereuponY operates, and closes ai self-locking circuit, including its,` own upper winding Yand the Winding of chain-control relay'CC." Relay 4kCC thereupon operates, and removes operating potential from conductor |50, thereby rendering ineffective the start key S at all The initial operating circuit-of relay CI (through its lower winding) is now open, but relay CI `remains operated in its self-locking circuit through its upper winding and the winding ofthe 'operated'relay CC. It isA tobe noted that conductor-| I8, over'which. the upper winding of any one of the relays CI, C2, and so forth, may become locked'l operated, is carried'through the -chaincircuitwherebyonly one such relay can be in a locked,v operated condition at the same time, thereby preventing' thesimultaneous indi- -vidualization of the system with two key sets. At its lowercontacts, relay CI grounds conductor |5I, thereby rendering eiective the normally ineffectivedigit keys in key set KSI, and lighting signal lamp H6. Upon noting the lighted condition of'slgnal lamp 6, the operator may Arelease the start keys and .proceed to actuate the digit keys of keyset KSI according to the number to be called.

ma RECORDING CALL No. 5.55

trol relay CC." This locking circuit is closed at the Yright front contact. of theflower armature of relay K5. At the left front contact of the lower,

armature of key'K5, ground potential is extended to start conductor |08, thereby starting the send.- ing apparatus into operation, as will be subsequently described.

Additionally, since none of the relays KI to K4 is operated, the grounding of start .conductor |08 results in the grounding of -each ofthe nor-l:

has been recorded. Since none of the relays K0 to Keisoperated, digit conductors toA- of this group remain .connected to the nouigrouncled start conductor it, indicatingfthat thersecond recorded digitis a 5.

.When keyli of group ||5 is momentarily operated to secure the recordation of the third digit 5 in the called Vnumber 555, relay'KI operates and locks to conductorl23, at the same time grounding conductor L of digit group ||2 as an indication that a third digit has eeen recorded. With none of the relays KH to K|4 operated, conductorsl to 4 in the third digit group ||2 remain connected to the now-grounded start conductor |08, indicating that the third recorded digit is a 5.

IAS. LOCKING START RELAY sT Start relay ST operates'responsive to the grounding of start conductor |03, thereby plac k ing ground potential directly on conductor' |52, normally connected with start conductor |08 through the back'contact of` armature 3 of relay 33| or" the digit counter. Relay ST isthereby locked operatedfand can be restored only during such time relay DI is in operated condition, the utilityV which will be 'subsequently explained; *j Relay ST also removes actuating potential Afrom guard` conductor |01, insuring that conductor '55E cannot be reenergized with actuating potential until start relay ST is unlockedand restored.; Y me. STARTING THE IMPULsE GENERATOR The impulse generator,- coinprising relays GI to G4, is started into operation responsiveto the grounding or conductor |52. When this occurs, relay Gl operates through contacts of relay G4, rollo i uhich relays G2, G3, and G4 operate in succes, on, the circuit of each such relay being closed at contacts of the preceding relay. When relay operates, it open-circuits and restores relay Gl, whereupon relays G2, G3, and G restore successively, and relay G4 reconnects relay The above cycle of operations is repeated continuously so longv as conductor |52 remains grounded. f v

Each of the relays G| to G4 is a fast-operating relay, but is rendered slow-restoring, as by the usual copper sleeve arrangement intended to be indicated by thevertical lines drawn slightly inside the contines of the relay structure. Good results are ohtained when acycle of the impulse generator occupies a time interval `of aboutrone second, each ofthe yrelays Gl toA G- then refn quiring about one-quarter second to restore after its circuit is opened, Y 1 v nis. TRAN'SMITTING THE INITIAL DIGIT BLANK The sending apparatus is arranged to transmit a blank. digit (no `impulses onthe'signal line) prelirnlnarlytc each number transmission v'The utilityA ofthis arrangement is twofold. 1t provides a spacing between numbers longenough to marl:

a clear distinction between the end of one transrnitted'number and the beginning or Vthe next; and'it permits ample time for the previously dei scribed digit-key and recording-relay operationsl to become completed Ybefore the transmission of= :ne first digit of thers'tnumber is begun, avoidB ing the necessity of the operator hurrying through the second and third keying operations. f The placing of the first ground impulse on conductor X by relay G2- of the impulse counterree sultsin the vclosure of a circuit throughcc'ntacts 2 of odd-control relay IO of the impulse counter, the winding of the rst impulse relay Il, andtheV chain contacts controlled by armatures 4 of relays i2to i5, and armature 3 of lrelay 1,6, to the ungrounded poleY ofthe current source. VRelay Il operates in this circuit and prepares at its contacts"2"a circuit for the second impulse-relay I2,v while Vat its contacts 3 it-'oloses a self-locking.circuit through the winding of relay IO. Relay IO does not'operate in this locking circuit for the time being', being short-circuited by the initial energizing path between conductor X and the lower terminal of-relay Il. l f. if.;

When the first impulse on conductor X is ter-1 minated, relay I| remains operated, and relayv IO operates, in the above-noted lockingcircuit. Relay IO opens a point in the associated odd-impulse path at'its contacts 2, while at its 'contacts ilit closes a point in the associated' even-relay operating path.

- vAsia further result of theoperationoi relay.v

Il, the grounded conductor |52 isextended through contacts oi relay Il to conductor XI., extending tothe digit counter, thereby operating the rst counting` relay DlV thereof in la' circuit path similar to that above traced for relayII of the impulse counter. lAmong othery things, relay DI disconnects impulse conductor Y from impulse conductor Z, thereby insuring that no impulse will be transmitted from conductor X over conductors Y and Z to relay R during transmission of the initial .digit blank now ensuing. Relay DI also connects grounded conductor |52 to armature 5 of each of the impulse relays I2 :to I5 of the inipulse counter, thereby preparing seliwloclring cir-- cuitsfor. each such relay to enable the initial digit blank to be completely transmitted. v j Upon the second grounding of. impulsecon ductor X by the impulse generator, the-prepared circuit for the second counting relay I2 of the impulse counter is thereby closed, through contacts 2 of evenncontrol relay IE, winding of relay 2,`contacts 2 .of relay Il, and contacts of relay IO. At itsarmature al, relay I2 first closes a selflocking'circuit through the chain contactsof the succeeding counting relays, and :then openvcir cuits-and restores relays Il and l0. :Relay l2 also locks its lower terminal .to ground, ythrough the winding of relay IE, its own contacts :5, contacts 1 of the operated relay Dl, and conductorfll Relay IE does not operate for the time being, being short-,circuited the-ground .potentialfon cQnductOrX.' 1- l l the second :impulse is terminated the sfiot circuiti is thereby removed from relay IE. Relay I2 remains locked operated, and relay IE operates in the locking circuit of I2. Upon operatingffrelay IE opens a point in the -associated even-impulse path at its contacts 2, a-nd at contactsI Il it closes a point in the associated oddrelay operating path.

When the third impulse is placed on conductor X,'rel ay I3 operates through contacts of the restored control relay IO, its ovvn Winding and contacts of the operated relays I2 and IE. Itvlocks itself to the source of operating potential at its armature 4, and then open-circuits and restores the) operated relays I2 and IE. Additionally, relay I3 at itscontacts 5 closes a self-locking circuit in series with the odd-control relay IO, to ground by way of contacts 6 of the relay DI and conductor |52. Y

At the end ofgthe third-impulse, relay IO operates in the locking circuit of relay I3 with results as previously noted, including at this time the preparation of a circuit at its contacts I through contacts 3 of relay I3 for the fourthV impulse relay I4.- l Y Relays I4 and I5 operate responsive to the fourth and fifth'impulsesL respectively, as described forrelays I2 and I3, each such relay, upon operating, restoring the preceding counting relay,

along with the then operated one of the control :f

lockedgoperated and control relay IO again re-V Relays IO Vand I5 are 4the only relays operates. oigthe impulse counter` then in operated condition.

When the sixth impulse is placed on conductor X, relay I6 is thereby operated, through contacts ofthe restoredeven-control relay IE, the Windinggof .relay I6, contacts 3 ,of relay I5, and contacts l of the reoperated odd-control relay IO. At its 'armature 3, relay I8 locks itself directly to th operating-current. source, and open-circuits and restores re1ays'I5 and IO, leaving relay I6 the onlyloperated relay of the impulse counter.

Y `It is to be noted that relay I6 has no contacts corresponding to contacts 3 of relay Il and contacts. 5 of relaysV I2 to I5, Wherefore I6 does not lock itselfoperated to ground, as is the case with each of the preceding counting relays. Accordingly, when the sixth impulse is terminated, relayfIG restores, thereby returning the impulse counter to its original normal condition.

The preliminary digit blank, having a length (about six seconds) equal to the time consumed by six cycles of operation of the impulse generator, lhasinovv been transmitted, and all of the relays of the impulse counter are in restored condition in readiness to reoperate as required for the transmission of the digits of the recorded call number.

y IAG. OPERATION OF THE DIGIT COUNTER "ieFrom v'an' operational standpoint, the ydigit counter (comprising odd and even control relays DO and DE, and counting relays DI to'D4) reY sembles the impulse counter, differing incidentally in that it contains only four counting relays in the illustrated embodiment, Whereas the impulse counter is illustratedias containing the previously described six' counting relays Il to I6. a

As previously indicated, the digit counter is controlled'over impulse conductor' XAI. A single impulse is delivered over conductor XI: o-tbe digit @4e-egress;

cnunteitffonfeacroiomplet operation of thelmi pulse Lcount'er.: t Aszfpreviously Lnotedpzthe, impulse toethe digit; counten-isiibegunI uponthe Aclosure of contacts I of relayyIZ.4 This impulse is con tinuedat contacts 2 of the, succeeding counting relays I2 to I6 so long as any oneof` them is in operatedacondition; 'untilztheA operation .of fthe impulse .countercis terminatedupon thetrestgration-:of .the last-.counting relay thereorto operate.`

Upon the initialfrgrounding of conductorXI, relay DI `fof theA d-igi.t.cdunterV operatesgas previously noted, through contacta-2.0i .relay DO, .the .Wind-v ing of relay DI and the contactchain including normally closed contacts controlled by armatures 2 of relays D2 and D3, and armature Lof relayD4. Relay DI locks itself :operated through odd-control relay DO, which relay operates in the lock-V ing circuit of relay DI responsive to the unground: ing of conductor XI upon the termination of the transmission. of the initialdigit blank. Relay DO, besides disconnecting the associated oddimpulse branch'fromi conductor XI at its contacts 2, places energizing potential on the associated even-relayoperating'conductor at its contacts'v l.

When the 'impulse counter starts its second cycle yof operations, during which it transmits the irstdigit of the recorded number, as will be subsequently explained, relay `Il thereof again grounds conductor XI, and this V.conductor is maintained continuously grounded at contacts of one Vor another of the succeeding relays of the impulse counter until such digit has been completelytransmitted. v- Y The second grounding of conductor XI results in the closure Vof 1an; operating.i,citenit.` through contacts 2 of even-,control relay DE, the Winding lof relay D2, contacts 2 of relay Dl, and Vcontacts i of 1elay.DOfor the second digit counting relay D2. Relay D2 .locks operating `potential on its upper terminalat its armature 2, and open-cir.- cuits and restores relays DI and DO.

RelayDZlalso locks itself to ground through the even-control relay DE andits own contacts 3, provided locking conductor L of the second digit group III. has been grounded, responsive to the operation of lone or vanotherrof key relays Kii to KIQ of the second digit group. .In this event, When the iirst digit impulse transmission has been completed, and conductor XI is consequently again ungrounded, digit-counter relay D2 remains operated, and yrelay DE operates in the abovenoted locking circuit thereof.

At the beginning of the transmission` of the second recorded digit,` conductor X! isl again grounded, whereupon the operating circuit is closed, through contacts 2 of the restored relay DO, the Winding of relay D3, and contacts i of relays D2 and DE. Relay D3 thereupon operates, locking itself tothe operate chain at its contacts 2, and open-circuiting and restoring relays D2 and DE. Then, when conductor Xl is again ungrounded at the end of the transmission of the secondV recorded digit; and provided conductor L inthethird digitsgroup H2 Vis grounded (at the Contacts of one or another of the relays KII to Ki) to indicatev that a third digit has been recorded, relay D3 remains locked operated, and relay DO reoperates vin the locking circuit, through contacts 3 Vof relay D3 and over the associated conductor L.` It may be noted that relays D3 and DO are then the only relays of the digit counter in operated condition.

When the impulse counter starts its cycle of operation pursuant to 'the transmission 'of the third recorded digit, and consequently again yLike relayl of the impulse counter, relay AD4 closes no self-locking circuit to ground potential. It accordingly, restores upon the ungrounding of conductor XI at the completion of the transmission of the third recordeddigit, bringing the digit counter back to its illustrated normal condition, in preparation for starting another number transmission consisting of a number-spacing digit blank, followed by the'respective Adigits ofthe Vrecorded number. Y

LA7. TRANSMITTING 'rf-IE FIRST RECORDED4 i DIGi'r 5 The next impulse delivered VVto impulse conductor X by the impulse generator, following the described clearing out of the impulse counter lat theend of the transmission of ,the preliminary number-spacing digit blank, results in the reoperation in the described manner of counting relay II of the impulse counter. At thistime, conductor Xi oi the digit counter is again grounded, thereby causing the described operation of relay D2 of the digit counter to occur, followed immediately by the restoration of relay DI.

Relay Di, at its armatures 4 to l, disconnects grounded conductorISZ from the locking armatures of relays 1 2 to I5 leaving such armatures supplied with ground potential only by way of conductors I to 4 of therst digit group I Iii, and contacts of the operated relay D2.

4I n the Vassumed example, number 5 55 being called, each ofthe conductors I to 4 of group H0 is grounded, each` through contacts of its corresponding one ofthe unoperated first-digit relays KI to K4 whereby locking potential is supplied forthe rst digit locking of each o f the relays I2 to I5 of the impulse counter. Accordingly, the operation of the impulse counter proceeds as previously described. That is, relays I2Y to YI5 operate successively following the operation of relay Ii, each such relay open-circuating and restoring the preceding counting relay. Relay I6,

being unable to lock, restores at the end of its operating impulse, again Ybringing the impulse counter to normal condition in .readiness for the transmission of the second digit of the number.

Through contacts vI of relays 12,110 I, conduc- `tor Y receives live impulses from conductor X Vduring the transmission of ther first recorded which the iirst countingrelay'II of the impulse ulse period, requiredfor the option'of re Ii, is employed as an interdigit timeY .interval to provide a time separation beine during the impulse ,period inV the rst digit over theillustrated signal line, to

's operated, for relay Il' has no contacts pulse conductors X and Y. This tween successive digits ofthe same number. This interval is .conveniently introduced just preceding Vea :h, dig it transmitted.

IAS., TRANSMITTING THE lsEeoND RECORDED DI GII5A With the impulse counter having cleared-out as previously described following the transmission of ther'st recorded digit, conductorXI extending to the digit counter isungrounded to cause operations toroccur therein as-previously described, pursuant to its counting operation. Y

`-When relay Il of the impulsecounter next rre- `sponds to count the inter-impulsefinterval preceding the transmission ofthesecond recorded digit,v it again grounds impulse conductor XI, whereupon counting relay D3 of the digit counter 'operates as previously described, followed immediately by the restoration of relay D2. The locking armatures 5 of relays I2 to I5 are thereby disconnectedfrom conductors I to 4 ofthe iirst digitgroup I'IB vandtransf'erred to the respective conductors `I' to 4A of the second digit group IIjI,

eachfof which latter conductors is'grounded asA previously'pointed out. Accordingly, the operation of relay II of the impulse counter pursuant to the transmission 0f the secondjrcorded Ydigit is followed by the successive operation of relays I2 to IIiQ'relay I6 restoring atthe end of its concerned operating impulse, again bringing the -impulse counter to normal position.

Five impulses are transmitted over the sending line during the second-digit operation of the Vimpulse counter, through'contacts l of relays I2 to I S, as described in connection with the transmission ofv therst digit 5.

rA9.TRAN si\nrfr1`NG.'rHE 11i-HRD RECORDED When relay II of the;impulse counter reoperatesV at the beginningof the third-,digit operation of the impulse counter, the consequent regrounding of conductor XI leading to thefdigit counter causes relay D4 thereof to operate as .previously described, followed immediately by the restoration of .relay- D3. v The locking armatures 5 ofrk relays I2'tovI5 are thereby transferred from conductors I to 4 ofthe second digit group III to the corresponding conductors of the third digit group II2, eachof whichis also` grounded as previously noted. Accordingly, the impulse countker repeats the described. cycleof operations as it transmits ,the third recorded digit 5. ,Liio. REPEATING'THE NUMBER TRANSMISSION When relay I6`of the `impulse counter restores at'the end of the transmission of the final imfpulse in the third digit' of thecalled number 555, and again'ungrounds conductor Xl leading to the 'digit'counten vthe liinal counting relay D4 of the digit vcounter thereupon restores, vagain bringing the digit counter intonormalcondition, coincidentwith the resumed'normal condition of theV impulse counter.- Theforegoing operations are' therefore'repeated asfdescribed vvfor solong `a -time as start conductonlremains grounded.

m11, CLEARING 'oUT' *ofany'operated one of relays CI, C2,and`so forth. jIn'the-present example, the "operated andlocked i 1:1 riay resides?esiinsivetothe snor rcuiting'o'f :itsupperwi dingjfAtf its vlciwer armature, relay CI removes'ground ypotential from the key-'supply'conductor |5| v-of thekey set KSI, thereby rendering the -keys ||3 to ||5 again in ef `t" al; and fextinlguishing. `:the sig'nal lamp -AlUpon'notingithat' signallamp IIB has become ertiguishedthe operator 'may release the key guiire'upon' :chain-control 'relay 4CC restores again joining conductor;'|.50 with guard conductor `III-'l ,-and' 'removing the :direct ground connection from fconductor.=|23.:A ii-:fr' z r-Ifwthe sending'apparatus shown in part l of Fig. llis'. at the moment inthe act of transmitting tli'eldigitlblank;relaylDl' of the digit, counter is in-operatedconditi'on and the clearing-out operatioi imriediately lI follows. the described *opening Vofllthe'grour'id connection to conductora |2/3. -Qn th-other' hand; if the 'impulse-sendingapparatus is at. some.r other portion of a number-transmit-V ting Ycycle, start conductor |08 isv connected, at thbackcontact. of..armature v:tot the thenrestored rel'ayDl, to conductor; I 5,2, grounded at thefront ,contact ofthejinner armature of start Y.'"elay.S."I. In v4this event, the sender-controlled ground potential on conductor |08 passes through the'rrightfront contact of the lower armature of `the operated one 4of the first digit-recording relays Ki to K5 (relay K5 in the assumed example). 1.' to -`conductor` I 23;.; thereby;` maintaining :sienne-potential* .0.112 conductor? l 23 egimerltel 'mezonerated key irelaysin loledgendiiiil. if?? thestimeibeing.fighi` if; 1." W'

When the imnulse; sendingkgapparatusj reaches its previously described digit-blank position, and relay DI ot the digit counter reoperates .assesses-ibas. transmettent dissguaeismf With start 'relayllST and Ichain-coritror'relay CC restored. Venergizing potentialv is reapplied to conductor |55. permitting operation to occur of ten'tial', and the' entire system. is in normal con- :one br" another off the chain -relays- CI .02,- and so Iforth: to individualize :the "recording: and send- "ingapparatus with any k'ey set at `which thestart "key isoperated as previouslydescribed. 1

HAs a-resultot tbeholding "arrangement iust dscribedfth operated recordingrelays are held. andthesending apparatusicontinues to function.

until'fanv partiallytransmittednumber has been completely transmittedgbefore the eouipment is permitted to clear-I out. Mutilationfof the final transmission-cfa series-of transmission of a number is thereby avoided. l

'- j Lila EXPLANATORY c H- A R'rr nieuwe. 4

` `Reference tothe eplanatory chart shown in Figf 4 will render more clear the foregoing derHildenotes the beginning ofthe next similar time period. during which the same cycle ofk operations is repeated; vertical line b denotes the beginning l2 @fling-time itervarduring which the first-frecorded digitffof the number transmitted; and vertical linsc'andl d denotethe .beginning of thel `*respectiveltimey intervals-f during which the secondand'third recorded digits aretransmitted. TheV lapse or 'time indicated by the spacing between li-n'es'a and bl'isfoccupied by the transmission'orthe-lpreliminary# digit blank, the primary purposeof which is to secure internumber spacing;aslpreviouslyfnoted. i Y f Horizontalline lX `represents conductor X of Fig;v llfThelieavy-lportions -of Athisline, numbered I to^24,-reprsent the twenty-four impulses which are-deliveredisuccessively toconductor Xv by the impulse generator during `th'e-single cycle-of op'-l eration's-Y pursuanttotransmitting number 555,. W-l'liileifthealigfhte'r intermediate portions of line X represent the respective inter-impulse intervals,

Lines Ilgte grefer respectively to relays-1| to I5 of the impulse counter, 1. Heavy porm tions breach such line indicate the time.interthe concerned. :relay is'foperortions 'indicating the-...timevintervalsduring theconcernedY relay is in restcredcondition. @From this'chart, it is clear 4tlfiat relays. Ivlfto Iiidrespond.respectively at the beginning of limpulses tnt` on A'conductor X; relays rIl to I5-restorerespectively at the beginning of impulses 2 to. 5.0m `lconductor X (being heldlocked operated duringthe concerned interimpulse interval, as. previously described; andthat relay-I6 restores at the end of the .sixthimpulsa there being no locking circuit for such relay. The restoration of relay I6 at the end of the sixth -impulse brings theimpulsemcounter back to normal condition, wherein vno relays therein are operated, as previously,v explained.- A

Thechart .of 4. further indicates that the A cperationsof relays Il to IE illustrated between 'Y vertical lines a and b recur in the same Way during the transmission ofv each Vof the recorded three digits of thecalled number 555.

Line Yv of Fig. 4 indicates the impulses transmitted by Way of conductor X to conductor Y of Fig. Il. The chart shows that conductor Y re- -ceives five impulses coincident With the second to sixthimpulses placed on conductor X during each of .the four time intervals ab, bc, etc. That is, conductor Y receives.Y all impulses transmitted to conductor-X, except the first, transmitted in a digit interval, such first impulse being the one which operates relay Il and not being transmitted .toconductor Y because relay Il has no contacts thereon for Ainterconnecting conductors X and Y` Line Z of Fig. 4 represents the impulses transmitted over conductor Z of Fig. 1 to repeating relay. RR. Line Z shows that no impulses reach conductor .Z of Fig. 1 during transmission of the digit blank, but all impulses transmitted to conductor Y during the respective recordeddigit intervals reach conductor Z. The absence of im- .pulses on conductor Z during transmission of the internumber-spacing digit blank is` secured by are then open, as previously explained.

Line Xl of Fig. 4 indicates the impulses dellv ered ovenconductor Xl to the digit counter. It Will be observed that the first impulse on conductor Xi beginsat the beginning of the rst impulse on conductor X and continues until the end of the sixth impulse on conductor X. This results from the fact that each of the relays Il to I6 grounds conductor XI, thus providing the desired long impulse thereon, which impulse is 75 terminated when relay I6 restores at the end of .contacts I of relayDI of the digit counter, WhichV Y on conductor Yoperations,

remains locked operated until relay "D2 operates' the beginning of the transmission of the first recorded digit. The chart shows that, similarly,

Since theimpulse counter, upon A14 i counting fand sending operation correspondingly sooner thanintheexample rst described.

V om the Vforegoingit Willbe'appreciated that Y the remarks concerning .other values of the second digit apply to other Values forthe third digit,

in thatany oneof the relays KII to 4Kili can be operated ink place of relay KI 5, disconnecting one or another of the conductors I to llof the third digit group -IIZ to give the third recorded digita correspondinglyreduced value. Y

being cleared out, immediately starts a new cycle of operations,

the relays D2 to D4 operate initially at thebeginsecond, third, and fourth impulses XI; thateach of the relays DZand D3 remains o jgierated until the nextsucceeding Vdigitncounter restores at the end orthefourth impulse on con- `ning of theV ductor Xi, returning the` digit countert'o rnormalv condition in readiness ier thestarting oi anew .cycle of operations thereof. 1B. frmmmmmg v einer immuni-numbers, Y 'Any one ofthe three vdigits ofi a' three-digit transmitted number can have any value'from 1 to 5, the vaiue'being determin'edeaccordingto which of the ve keys in theconcerned lone of groups H3 to H5 is operated'to record such'digit, resulting in the operation ofjthe corresponding one of the associated group of -liey'frelays For example, if the first digit of the' number is 4 instead oi 5., relay K4 is operated instead of relay K5. Conductor i of the first-digit group IIO is then vdiscormected from conductor lfconductors i to 3 of the same group being left connected. In this event, when the iinpulsecounter the first-digit cycle of operations'with relayDZ of the digit counter group ilu deprives relay Iscr. locking potential. Accordingly, relay I.; restores at the end'of the impulse Which operated itjand consequentlyat the end of the transmission of theiourth'impulse .in the rst transmitted digit 'of the number. A Ihe e ,eration of relay'Ib at'this time clears out' lthe impulse counter to prepare it for :a new .cycle Yof and removes ground potential from conductor Xi tol preparethefdigit counter for adrance to the second-digit position.

milarly, iiany one of the relays KI to K3 is operated instead of either relayKi or K5, the corresponding one of conductors I to 3 in group is ungrounded; causing the corresponding, one the i. pulse counterrelays I2 to AIll-to failr to .ci-z operated during .the `transmission of the rst .f i corded digitin the number. rThe current cycle 'oi' cperationsofthe impulse counter is accord` ingiy abbreviated tothevtransmission o. one impulse, two impulses., orf-threel impulses, to relayY dependent upon whichof lthe three digit values under consideration has beenrecorded for first digit. Y

' Sii-iiiarly, ii the second digit'has a value of from l to 4, the corresponding oneY or the key 7s K6 to K9 is operated in place of relay KIU.

s event, any operated one Is grounds the lockingconductor Las ded for reha-y K I e .l andadditimrially ungrounds Q concerned oneoi conductorsl toi-4 in" the second digit group HI. Accordingly, the concerned one oi' countingrelays I2 to I5 fails to lock @per during the transmissionof theA second recorded Y.digit (with digitfcounter relay D3 in operatedV condition) v terminating the second-digit in operated 'conditionfthe absence of ground potential on lconductor 4 of reiay operates; and that relay D4 goes through the interdigit spacing is independent of the nurnber of impulses .in the digit last counted, for the r spacing intervalY is introduced by the time inter- .two digits, thev key set operator operates a. hey of group I I3 according to the value of the rstdigit and a key oil group IIA according to the Value of the second digit,` but fails to operate a key of group .I I5. vIn-this event,. operat ions as previously described occur to. cause transmission of the pren liminary digit Yblank,.followed by transmission of the two-.recorded digits of the number. Ihe transmission ofthe second recorded digit or .the

.number occurs, as described, with relayfDS of v ,the ,digitA counter in operated condition. In .the foregoing description it Was pointed out that relay 'D3 locks operated through relay DO and over conductor L in group. I I2, when the number being called contains three digits. 'With a /tvvo-digit number recorded, conductor L of group .H 2 is not grounded, for Vnone of the relaysfKiI to Kl is then in operated condition. In this event, relay D3 closes :nolocking circuit for itself (at its armature 3`V and associated contact). Accordingly, relay D3 restores responsiveto the: ungrounding oi conductor XI, next ensuing, at the endV ofthe second transmittedrdigit ofthe number.; The

.restoration of- D3 in this event completely clears out the digit counter for a new'cycle of operations, at the beginning oftvhich relay Di again operates to control the transmission of the internumber-spacing'digit blank,.pursuant to the next cycle of sendingoperations.

- ID. Transmitting single-digit numbers f When a single digit number is to be transmitted, a key in group H3 is actuated to cause one or anotheror key relays KI to K5 to operate, but none 'ofthe keys in groups IM and H5 is operated,

Vwhereby all relays Kto KI5 remain in normal position. In this event, neither of the conductors L.in groupsl I'I vand II2vis grounded. Accordingly, when relay D2 of the digit counter operates to -connect conductors I to 4 oi the next Y ductorL of digit group III.

digit group' IIII to the circuit conductors of the impulse counter, relay D2 failsto lock koperated because of the absence of locking ground on; con- As a result, when conductorXI` is nextungrounded, at the :terne-.ilu nation .of the iirst-digit` counting operation of the impulse counter, relay DZQimmedia-tely reu stores and returns the digit counter to normal condition, whereby a new cycle of operations is commenced Ato immediately repeat the transmis `Vsion of the single recorded digit, as soon the Yrus.-

internuniber spacing operation of theimpulse vcounter has again occurred.

x Regulatingthe internumber space internal-v Thelength of theinternumber space interval (of the previously described digit blank) can be reduced as desired by omitting connections between armatures 3 to 'l of relay DI 'of lthe digit counter. For example-if the connectionf between armatures 4 and'5 of vrelay Dl issevered, the previously described f locking circuit for relay *I5 of the impulse counter', duringv transmissionhof the digit blank, opened with fthe `result"that relay I5 does not lock during the transmission of the digit blank. The impulse counter then-clears out at the end of the impulse effective iooperat'e relay I5. In this event,the lengtliof the spacing digit blank is reduced by one impuls'cyclefon conductor X, such digit then occupyinglonl'y ive impulse cycles instead of the six indicated in Fig. 4.

If the connection betvveen'armatues 5` and r' of relay DI is severed, relay I4 of the `,impulse -0 counter fails to lock during transmission of the digit blank, in which 'case the *length 'of V`this spacing digit is furtherreducedto four `impulse cycles.V i

If the connection between armatures 6 andA 1 of relay DI is severed, relay I3 fails to lock, giving vthe digit blank'only'a three-impulse length. Finally, if the connection between"armatures"'3 and l of relay DI issevered, only relay Il of the impulse counter can lock operated during trans- UU mission of the digit-blank, in which event such digit consumes only'the time ofthe two impulse cycles on conductor X required for the `successive operation of relays Il arid12. The operation. is then terminated when relay I2, failing to lock operated, restores and brings the impulse counter to normal condition in readiness forstarting transmission of the rst recordedldigit'. .o v

IF, Clearing out from anotherflcey set f The clearing out opeations previously d escribed as occurring'f responsive to 'operation'f;*of the release key R at keyfset KSI maygbe'performed at any other key set, `'such asKSZ, independent of with which key set the system is then individualized, for conductor VH8, `which, isV

grounded to cause the 'de'scribd' clearing operation, is com iontoA all the key sets, jas iridicated, and operationofrelease lkey R at -an`y key set grounds this same conductor, to thereby short-circuit and restore any operated one of the chain relays Cl C2, and so forth.- This arrangement enables a key set operator who Vmay have a more urgent code call to impress on the system to clear out the systemto that. end before the system is cleared out by the operator who originated the call being currently transmitted. Additionally, if an operator should be called away from his keyset station without clearingV out, 'an operator at any other key set can perform the clearing-out operation.

IG. ATransmittz'ng entrance signals Referring now to theentrance group comprising relays I to 5'(part 3 of Fig. '1) and associated equipment, the operation of the system to transmit entrance signals will be described,

In many establishments, a Watchman or similar person is on the premises continuously during non-business hours. The duties of such watchman ordinarily include admittance to the premises of any authorized persons. The watchman is expected to make regular tours .of the premises andis accordinglyvnotlocated continuously at any one Station,Y :nexus -..according1y. lconveniently called over the general calling system, through operation of signalling devices SD.

Many establishments have a number of entrances. The illustrated arrangement is such 5 that the Watchmamon being called from any .fentrancal is informedof the identity of such entrance. s 4

Thefentrance group of call relays comprises relays' I to 5, .providing for any number of en- 10 trances upto five.- At each entrance, a push button such asgIZl may be provided to cause the operation ofthe v,associated entrance relay. Associated with each entrance is a normally V wclosed stop buttonfl 22, used to unlock and restore the associated entrance relay, such as 5.

--'Ihe entrance group ofequipment is arranged to be placed in operative condition by the closing Acica', conveniently located entrance key EK, v.which may bey closed only during non-business o Vhours.` f

With the key EK operated, if `the start push button |2I atthe entrance with which relay 5 is 'associated be operated, relay 5 operates and -lgcks to ground through its own contacts, con- 4tffllfcts,enf stop.,button V|22, and contacts of the entrance key EK. Relay 5 also closes an operating circut for relay K5 of the first-digit group of recording relays, provided no other one of the relays Kl to K5 is in' operated condition. If o no other one of the relays Kl to K5 is operated, then relay K5 responds and extends its operating ground potential to start conductor H38 to start Vthe sending equipment into operation. Since noneof the remaining key relays K5 to Kl5 is geperated, the equipment functions as previously described to transmit a single-digit number, and the digit valuepf this number will be 5 lwhen relay K5 is the one operated, `by entrance relay 5. 1 When the watchman responds to the entrance ,m signahhe may terminateV the signalling operation Vandlclear out the equipment by momentarily .operating push button |22, which may be con- .veniently located near the concerned entrance. Relay 5 is`unlocked and restored by operation of button |22, opening the initial circuit of the V associated relay K5, and the latter relay promptlyffie'stores, provided start conductor |08 is fn t at the moment held grounded by the sending `qui`p`ment. Inthe latter case, the restoration of relay Kisdelayed until the sending apparatus reaches the internumber portion of its cycle, as previously described.

It' will bel app-arent that the other relays 'l to 4of the Aentrance group similarly control key vrelays KI to K4 respectively to cause transmission `Q f the respective call numbers 1 to 4. y' The rst and second upper armatures of key re llaysKl tol K5, together with their associated Acontacts and the illustrated interchaining connections,'are 'for the purpose of avoiding interference `in the 4event that operation of one or more additional Aentrance relays occurs before the watchman has responded and cleared out a i previously operated entrance relay. Suppose, for example, that entrance relay l becomes operated and locks'while entrance relay 5 is in operated condition and is maintaining key relay K5 operated. In this event,the grounding by relay i of the lead extending to relay KI is of no immedi- ,70 ateeffect, for operating potential is removed from the common chain-end conductor l55 at the contacts of relay K5. Operating potential is removed from'conductor. l 55 at the normally closed :1;contacts, controlled by the' second upper armature .oiianypperated one ofi the relays KI to K5.

When relay K5 is subsequently restored, jresponsive to the restoration of relay 5 as described, operating potential is replaced on conductor |55, whereupon the prepared circuit for relay KI becomes effective. Relay Kl thereupon operatesA IH. Alarm operation As previously noted, the equipment illustratedl in the upper left-hand corner of rpart 1 of Fig. 1 is provided for the sounding of a distinctive alarm over the comm-on code-call system, when desired. For this purpose, an alarm box such as is provided, and any vdesired number of similar alarm boxes may be connected in parallel therewith. A common use for such an alarm box is to indicate that a re has broken out on the premises, or that some other emergency condition has arisen. l

When the contacts of alarm box |00 close, relay responds, thereby closing a circuit through contacts Iof key |03 for relay |06. Relay |06 applies ground to start conductor |08 to start the sending equipment into operation, and it `directly connects conductor Z to conductor X, causing each impulse from the impulse generator to be transmitted to conductorZ. The result is the delivery of a continuous succession of impulses to signal devices SD.

When the alarm condition is ended and the contacts of alarm box |00 have been opened, relays |05 and |06 restore successively, and the sending apparatus ceases operation responsive to the resultant removal of ground potential from start conductor |08.

Key |03 is provided to disable relay`j|05 in the event that the contacts of the concerned alarmVr box are not promptly reopened on thetterinination of the alarm condition. Upon being'operated, key |03 disconnects the front contact Vof relay |05 from relay |06, permitting relay |06 to Vrestore and terminate the alarm signal. Key |03 further connects the back and front contacts of relay |05 to signal lamps |0| and |02. Lamp |02 thereupon becomes lighted as a signal that relay |05 is still operated. f Y

When the alarm circuit is 'subsequently 'restored to normal condition, permitting relay |05 to restore, lamp |02 becomes extinguished and lamp |0| becomes lighted as af'sign'al that the alarm circuit is now clear. The operator may then restore key |03, extinguishing lamp |02 and again preparing a circuit for relay |0|. '4 Key |04 is provided to enable the alarm condition to be initiated by a key set operator, as from direct observation or from a telephone report.

When operated, key |04 operates relay |05 with, results as previously noted. Relay |063y.restoreseY when key |04 is next opened. Y n

It will be apparent that the Valarm condition 11A. cazzingivo. '555 A detailed description of the operation ofA the modied system shown in Fig. 2 will now be given',`

forwhich purpose it will be assumed that the 05. takes precedence over any other kcall that may beY operator at key set KSI', part`2 of Fig. 2, desires to transmit call'number 55,5.

. UA1. RECORDING.k CALL No. 555

The'op'erator at key set KSl may rst record call No. 555 Aby operating key 5 in each of the digit columns 2|3, 2|4, and 2|5.- The digit keys of this key set being locking keys, the record of the called number isretainedthereori. The key set operator will of course restore any operated ones of theremaining digit keys of the key set, to the end that only the vdesired key in each of the columns 2|3 to 2|5 is in operatedcondition.

IIAz. INDIVIDUALIZING'THE SYSTEM WITH KEY y SET Ksl The operator at key set KSI may now operate 'non-locking start key VS' momentarily to cause the system to become individualized with such key set. Key Sv applies ground potential V(oblead O in cable CAI. The groundingof conductorO, if the ksystem is in normal condition,`

closes a circuit through the operate Winding of relay Ci', to battery by Wayof contacts of chaincontrol relay CC. guard conductor 201,4 and contacts-3 of start relay ST'. Upon operating, relay Ci closes a self-locking circuit-.for its righthand winding, through the winding of relay CC. Relay CC thereupon operates and` disconnects guard conductor 201 from conductor 250, thereby f disabling any remaining relays C2', and so forth, from operating. Y Relays Cl' and CC remain operated in series thereafter. Lamp 2 I5 lights in parallel with vthe right-hand winding of relay Cl Relay CVI' lconnects conductor-ST in cable CA| to start conductor 208; connects digit leads to` 5 in cable CAI respectively to mark leads MIk to M5; and connects leads L2 and L3 respectively to locking leads L2 and L3. Y

HAB. STARTING THE SENDING OPERATION With'key Bof digit column' 2|3, and individualizing relay CI', operated, a circuit forvrelay VST' is closed: from ground through the lowercontact pair of such key 5, conductor ST in cable"CA|,

contacts of the operated relay CT', start con-v ductor 208, and thence to operating potentialby way of the winding of start relay ST'. At its contacts 3, relay ST Vremoves operating potential from guard conductor 201; at its contacts; it grounds conductor 209; and, at its contacts 2, fait closes a self-locking circuit to the grounded -'"-'c` mductor 209 by vway of back contact 3 of relay DI'. As described in connection with Fig. 1, cyclic operation of the impulse generator comprising relays GI to G4 occursresponsiv/e to the grounding of cnductor209.1 Impulses'are trans-y mitted alternately over "conductors 26| and X".

vgfghiurther resultofv the' application' of ground potatial' to conductor 209 is the grounding of conductor XIv through contacts of relay I6jof the impulse counter. The 'grounding' of conductor X l (corresponding in function to conductor X of Fig. 1) results in the operation of relay DI',

liminarydigit blank. At its armature 3 ,and front contact, relay Dil' closes aself-lockins circuit through control relay D0', to secure the operation of the Alatter relay when the instant impulse on conductor Xlvr is terminated. At the the self-locking circuit of relay ST to permit clearing out tooccurduring the transmission of any preliminary digit blank, about as described in connection with Fig. 1.Y

tained over ground conductor G in cable CA to associated Vwith the transmission of the pre-v back contact of itsarmature 3, relay DI opens IIA."TRANSMITTING THE INITIAL I )IGIT BLANKA.;

Preparatory to the `transmissionof the initial digit blank, relay D|'.,of`.the-digit counter disconnects conductor Yi from conductor VZ at Aits contacts I, While at its contacts II it connects the current-supply conductor 200 (receiving its current supply through protective resistor 260 and thef'contact chain controlled by relays IIl to 16') to-conductor DCB (digit control blank) therebysupplying operating potential to the upper Winding terminal of the first counting relay II? of the impulse counter. v

With conductor DCBenergized as described, to apply energizing potential tothe upper Winding terminal of relay'I I', the rst grounding of impulse'concluctor 26| by the associated impulse generator results in the-operation of relay II' through vcontacts 2 of relay IO. Relay II' closes aself-locking` circuitY at its contacts 4 to grounded conductor 209 to As ecurethe operation of relay 10" atthe end Vof'the impulse on conductor 26I;"at its contacts-3', it locks operating potential. (through chain contacts of the succeeding counting relays) on its upper terminal; at its contacts 2, it prepares to place operating potential onthe upper Winding terminal ofV the next succeeding counting relay 12'; and, at `its contacts' I, it joins impulseconductor X to conductorY; but the latter operation is of no effeet at this time Y(during -transmission of the digit blank)A for VconductorsY and Z areA now disconnected at contacts -I of the operated relay DI'.

When the rst impulse on conductor 26| is terminated, relay VIOl operates in the locking circuit of relay II', and supplies operating potential to the upper terminal of relay l2,` through contacts 2 of relay II. Y Y

Relay I2' operates through contactsv of relay IE', responsive to the next impulsejon` conductor 26|, whereupon it locks itself to conductor 209 .throughrelay IE; .locks operating potential ...Relays I3? fand I4 respond respectively to the third and fourth impulses on conductor 26 I, and relays I5 and I6 respond .respectively to the ifth and sixth impulses. Each such relay, on responding, restores the preceding counting relay,A along with the associated one of the control relays IOand IE'.V Each of the relays II' toI5' locks operated as described forY relays II and I2', but relay I6' does not lock operated independent of conductor 26|. Y

When relay I6 operates, besides restoring relay 'I5 and the associated relay IO at the contacts controlled by its armature I, it disconnects impulse conductor Xlia't its contacts 2, therelbyf'terminating theimpulse tothe lattercondu'ctori' `-When l'this voccursyrelay DO operates' inv the"'locking'cirouit of relay'DI' to apply operating potential to the upper terminal of relay D2', through vits own contacts I and contacts 2 ofthe operated relay D I Whenthe sixth` impulse on conductor 26| is terminatedfrelay I6', not having locked operated independent of such impulse conductor, im-

nal -iIl mediately `restores, returning .thee-impulse c cunter toits illustrated normal condition.' .Y Thepreliminary digit blank, having a duration equal to six cycles ofthe impulse generator, hastr now been completely transmitted.

Inkv lth'eillustrated.- lexampla conductor DCB extendsfrom armature 4- oi relay DI' to the upper Winding terminal of relay Il', VIf alles-V ser duration isf desired for the preliminary digit blank; 'conductor DGBl-may be disconnected A fromn thefupper-Windingtermihal of relay -II 'y -and con-V nected to the correspondingterminal of one or another ofVv the relays VI 2, to I 5'. Connection of conductor YDCB tohtheupper Winding terminal transmission of the blank.' 1IA5. TRANSMITTING THE FIRST RECORDED DIGIT i Y Whgenrrelay I6 restoresV at the end of. the

transmission of the, preliminary. digit blank, it' again'` grounds conductor-XV, thereby operating counting relay D2 through, contacts-2 of relay DE., .the `operating .circuit including' contacts -2 and Lof relays DI and DO.. .i

Relay .-D2,'. locks operating .potentialon its.. Winding te-rminal. at Vits .armature 2 and front. contact, at the Sametimeopen-circuiting .andU restoring relays DI and `D O'.v Conductor DC is thereupon disconnected by relayY Dif.

At itscontacts 4relay D2 connects operating` potentiaL-obtained over conductor.. B and resistor. 260, ,toco'nductor DCI (digit controlfl'rst), With the arupper contacts of keyE of the first .colurnn2l3` closed, the operating potential is further extended to conductor 5 in cable CAI, and thence, through contacts -of the operated chain relay CI and markingconductor M5, ,to the upper rWinding,terminal of the first countingjrelay4 II ofthe impulse counter.

Responsivetn the-next ensuing impulse on conductor 26|, relay II', Whose upper winding terminal is. supplied with operating potential over `-conductor.,M5 as above. noted, operates through contacts of relay IO' withresults substantially as aboyedescribed in connection with the transmission of the preliminary .digit blank. At this, time, with relayDI, in restored condition and conductorsY" yand Z consequentlyreconnected, the vclosing of contacts ,I of relay II yresults in the joining of conductors X' and Z. "Accordingly, whenrelayGZ `of the impule counterresores to terminate the instant impulse over conductor 26|, it transmits an impulse over conductors X', Y', and Z to repeating relay RR shown in Fig. 1. 60

Relays I2 Y to I6' respond as previously described tothe impulses respectively succeeding the one serving to operate relay II. Conductors X'A and Y are maintaipedlionncted together `by contacts I of relay/ S121 kto I5', whereby veimpulses have been Vtransmitted over conductors fapd AZ. tq 1jelay'RR by ,the timek relay I6' operatesfto restore relaylandthereby again separateecnductrs X' and Y', f

The impulse counter is again brought'to norfmal condition by the'rstoration of relay I6' at the termination 'ofthe sixth impulse received over cgnductorll bythe impulsev counter pursuant t0 the transmissionpf. the. rst recorded digit 5 of the called number. With conductors X and Y again separated, no impulse is transmitted to the repeating relay during the intervalbetween the last-named impulse over conductor 26| and the next succeeding impulse thereover, whereby an interdigit space is introduced, one impulse cycle longer than the interimpulse space, and of a length similar tothat of the interdig'it space introduced as described in connection with the operation of the apparatus disclosed in Fig. 1.

IIA6. TRANSMITTING THE SECOND RECORDED DIGIT When relay I6' ungrounds conductor XI' at the end of the transmission of the rst recorded digit, digit-counter relay D2' `remains operated, and control relay DE' operates, over the following self-locking circuit, effective onlywhen the number called contains a second digit: from ground over conductor G in cable CAI, the lower contacts of any operated key in column 2I4 (key 5 in such column in the assumed example), conductor L2', contacts of the operated chain relay CI', second-digit locking conductor L2, contacts 3 of the operated relay D2', winding of relay DE', winding of relay D2', and thence to operating potential through the operated armature 2 of relay D2 and chain contacts of theassociat-ed succeeding counting relays. y

- Upon the restoration of the non-locking relay I6' of the impulse counter at the end of its operating impulse over conductor 26|, the consequent regrounding of conductor XI' closes an operating circuit, through contacts 2 of the restored relay DO', for relay D3', by way of contacts I of relays DZ' and DE. Relay D3', at its contacts 2. locks itself to operating potential through contacts of relay D4', at the same time open-circuiting and restoring relays D2' and DE'.

Relay D2', at its contacts 4, disconnects energizing potential from conductor DCI, thereby removing marking potential from all of the keys in column 2 I3 of KSI', thereby removing the impulse counter from under the control of the keys in this column. At its contacts 4, relay D3' appli-es energizing potential to conductor DC2, extending to theupper contacts of the keys in the second-digit column 2I4 of KSI', whereby the impulse counter is placed under the control of the keys in such column. With key 5 in this column operated, the operating potential is further extended tofconductor 5 in cable CAI, and thence through contacts of relay CI', and mark conductor M5, to the upper winding terminal of relay II' of theimpulse counter.

The cycle of operations of the impulse counter described in connection vwith the transmission of the iirst recorded digit 5 is now repeated, during which the ve impulses corresponding to the second recorded digit 5 are transmitted over conductors X', Y', and Z' to the repeating relay RR.

IIA?. TRANSMITTING-THE THIRD RECORDED DIGIT 5 When relay I6 ungrounds conductor XI' at the end of the transmission of the second recorded digit, digit-counter relay D3 remains operated, and control relay DO' operates, in the following V locking circuit, effective only if the number re- 22 controlled by armature I of relay D4'. to operating potential. Y

Upon the next ensuingrestoration of nonlocking relay I6", the consequent regrounding of conductor XI closes a circuit through contacts of the restored relay DE' for counting Arelay D4',` supplied with operating potential through contacts I of relays D3 and DO'. At its contacts I, relay D4' locksoperating potential on its upper winding terminal, at the same time open-circuiting and restoring relays DO' and D3'.

By opening its contacts 4, relay D3' removes operating potential from conductor DC2, thereby removing the impulse counter from under the control of the second-digit column 2M of key set KSI p At its contacts 2, relay D4' applies operating Y potential to conductor DC3 (digit controlthird), extending to the upper contacts of the third-digit keys, column 2I5 of KSI', whereby the impulse counter is placed under the control of the keys in such column. With key 5 in this column operated, the operating potential is further extended to conductor 5 in cable CALandl thence, through contacts of relay CI' and over mark conductor M5, to the upper winding terminal of relay II "ofY the impulse counter.

The cycle of operations of the impulse counter described in connection with the transmission of the rst recorded digit 5 is again repeated, during which live impulses corresponding tothe third recorded digit 5 are transmitted over conductors X', Y', and Z' to the repeating relay RR.

IIAS. REPEATING THE NUMBER TRANSMISSIVON*r When relay I6 of the impulse counter operates at the end of the transmission of the third recorded digit 5 to un'ground conductor XI', relay D4 immediately restores, not having locked operated independent of conductor XI'. The restoration of relay D4 clears out the digit counter, returning it to its illustrated normal condition. The impulse counter is cleared out and returned to normal condition upon the termination of the instant impulse over conductor 26|, following which operations as described recur so long as start conductor 208 remains grounded, to hold start relay ST' grounded.

IIA9. CLEARING OUT When the non-locking release key R at key set KSI' (or the corresponding key at KSZ') is actuated to clear out, no effect is produced until the sending apparatus again reaches the digitblank, position, whereupon relay DI grounds release lead RL. Ground is then transmitted through key R', and over conductor H in cable CAI, to the right-hand terminal of chain-control relay` CC', lthereby short-circuiting lamp 2I6 and the right-hand winding of the operated chain relay CI. Consequently, lamp 2I|6 becomes extinguished, and relay CI' restores, opening the connection between its right-hand windingv and that of relay CC'. Relay CI also disconnects c-onductors ST, 5 to I, L2', and L3' in cable CAI lfrom the corresponding common conductors, terminatlng the individualizatlon of the system with key set KS I The described restoration of relay CI', by disconnecting conductors ST and 208, removes the ground connection initially applied to start'conductor 208. Since this operation occurs while re lay DI' is operated, relay ST' is not then lockedy 23. toi-JZIJSetl-iereby terminating operation of themr. pulse generator, the impulse counter; and the digii'. zco unter.`

V:incident to the clearing-out operation,l relay' l? restores, ungrounding lead RL, whereupon relay CC restores; again energizing conductor 2503120 permit individualization of the system with fkeyfset. vf 'rIhe operator may release key R upon notingthatthelamp 2I6 has "become extinguished-" Y 11B; Calling other 3-digit`nnmbers I. y .Anydesired 3-digit number other than the pre- Vigusly assumed number 555 may be set up .on thekeygset, Ksl'. For-example, ifV the nrstfdigitef the called number is 4, key 4 of column 2 iii, is operated instead of key 5, In 4thisevent,,when digitcnnrol lead DCI is energized,energizing-potentialis ktransrnittedr (over conductor 4 of ,cablel CAI. 1rd .hrough Contacts of relay-CI) to mark condiretowMlig'.- instead of to Amark conductor M5. Markfconductor- M4 extends to the upper windingfterminalfof thevsecond counting, relay I2? of thefimlllise. counter; whereby relay I2' is i-nitialll7 operfrated,1,in,stead oi relaygII, at the beginning oifdthetransmission of; the rst recordeddigit. As Aa resultmoneless :impulse is requiredV 'cooperate theimpulse counterthrough the. shortened cycle n erations, resultingfin-pnly four impulses beansmitted to the repeating relay. Similar-` ark, eonductor-,MS .,istheone energized if `key B .is' heone` operated infcolumn 213, whereby the @rale eff.: @regeringen the-impune counter isili?- thershortened in that relay I3' is the one initially operated. Y

If the'second key in column 2I3 is the one operateiijm'aifk conductor M2 is'the' one energized, resultingin the initial operation o f counting rev layAI in which case only two impulses' are transu mitted the repeating relay. Y

1- Finally, if'key I o i column 2I3 is operated, niarkl conductor MI isthe one energized, 'resulting in the 'initial' energization of relay I5 of the impulse counter, "in which event only a single impulse is tfrisinitted @eine repeating relay as 'meinst re corded digit. y sinilariy, tne'seeond and'third recorded digits may have any value of from 1 to 4 instead of thel described Value of 5, provided the corresponding keys are operated in columns 2 I4 and 2 I 5 of KS i IIC. Calling Z-clz'git numbers If .the number being called contains only two digits, the operator at key set KSI actuates thel desired keys in columns 2 I 3 and 2 I 4, and restores any key which may be actuated in column 2I5. Lockiliisr conductor L3 in cable CAI is accordingly not grounded, wherefore locking conductor; L3 is not grounded. In this event, counting 4relay D3 of the digit counter cannot lock operated irldependent of conductor XI. Relay D3 therefore restores at the end of the transmission of the Y second recorded digit, returning. the digit counterto normal condition. The new cycle of operations is thereforestarted at 'the end of the transmission of the second recorded digit.

IID. Calling single-digit nun/,b'ers'-r When a single-digit number is to be called, the operator. at key set KSIv operates the desired key inffcolumn 2I3, and lrestores any operated one of the remaining keys of the key set. Accordingly, neitherconductor L2 nor L3 is grounded. In this event, counting relay D2 of the digit counter cannot lockoperated independent -of conductor XI Relay.' .132.' q accordingly ,restores ,at thev end io'f the;

l fcoNfrnoL STATION csiA Y .The thecallinlgcontrol station, station CSI in the Aasl-v sumed. example. For thilspurp'ose, the operator actuatesl start key S2, therebylextending ground potential tothe left terminal of @ne loweriylinfdi-` thencefby* way .of guard' concerter" 2`n1 to die source of operating potential as show'rin'ligl?? Vating potential. Relay LIMLP ith'rupnfopates 'HIAZ; N TRANSMITTING ANWB-Economo THEV to breakcnnection .with'impulse conductor 302,

preparatory' t'implulse .traIisfiis sior'rl` Relay 'IMP-fy also connects the `Aupper winding terminal of chain-control' relay CC.2 tolockingconductor 301, therebyconipleting' vthe"prepared locking circuit for tli'r`e`1pper winding? oiiel'ay 'C'I2f Relay CC2 thereuponopeates `inthe noted locking circuit.

At its *upper contatslit connects the grounded- (theholdinglwinding) o'f control magnets 304 to 30B"o`f registers RI `to R3`respective1y. "No immediate operational effects producedn by theV energization of these holding windings.

With relays IMP and CC2 operated, the receiv-l Y'ing circuits are now conditioned for the setting of the register RI.V This fact is indicated to thel operator by the g'lowing'o'f signal lamp 3I6 in1$liihlYMlf a' The Vopera-turf.at-control station CS I may now` operate the calling-ideviceizCDin accordance with the rst -digitin the desired number, whereuponr theeimpulse; contacts of the calling device separatei` momentarily `a corresponding#` number oftimes, :each timeiopening :the `previously traced` :circuit forrelayIlVlP,

Relay IMP momentarily restores each time its circuit is opened at the-calling device CD. Each f il fINDIVIDU-ALIZING ,TI-IE,` ySYSTEM 'WITH system mustnrst te individua1ized'with-- In the event that the transmitted impulse iseries contains further impulses, the receipt of thersecond impulse bythe operate winding of magnet 304 results in the closure of the second setof register contacts 2, preceded slightly by the opening of contacts I. That is, upon the closure of any of the register contacts 2 to 0 of the register RI, the precedingregister contacts open just before the new closure is effected. By theoperation now being described, one cr another of the marking leads MI to Mof the register Rl'is connected to the first-digit control lead DCI, preparatory to the transmission of the `first recorded digit.

With off-normal contacts ON of the register RI closed, on each reoperation of relay IMP, -ground is extended to the lower Winding terminal of transfer relay TRI: from the grounded upper armature of relay IMP, conductor 30|, off-normal contacts ON of register RI, and the normally closed contacts controlled bythe lower larmature of relay TRI. Relay TRI is so wound and'adjusted that it does not operate during the vibratory actionof relay IMP while the remaining impulses of the series are beingA transmitted.l But, relay TRI operates when relay IMP comes to rest, in operated condition, at the end of the fr impulse series. At its lower armature, relay TRI locks itself directly to the grounded conductor 300, at the same time opening its initial operating circuit. At its inner upper armature,`relay TRI disconnects conductor 302 from the operate winding of magnet 304A of theregister RI and transfers it to the corresponding winding of magnet 303 of the register R2, preparing the register R2 to receive the second transmitted digit in the number being called.

When the calling device CD is operated in accordance with the second digit in the desired number, the resulting impulses transmitted over conductor 3.02 by relay IMP are delivered, through contacts of the operated relay TRI and contacts of the unoperated relay TR2, to the operate Winding of magnet 303. The register R2 operates as described for the register RI, connecting one or another of the mark leads MI to M5 to the second-digit control conductor DC2, according to the value of the called second digit.

When relay IMP comes to rest in an energized condition at the end of the second digit, transfer relay TR2 (having characteristics similar to those of TRI) operates over conductor 30! and through off-normal contacts of the second register. Upon operating, relay TR2 locks itself directly to conductor 300, and transfers impulse conductor 302Y from the operate winding of the second register to the operate winding of magnet 306 of the third register R3. Accordingly, register R3 responds as described for the registers RI and R2 and records the value of the third digit by :connecting the third-digit conductor DC3 to one or another of the mark leads MI to M5.

IIIAS. TRASMITTING THE RECORDED NUMBER Transmission of the recorded number (by the apparatus shown above the broken line 3--3 of Fig,V 2),.is started responsive to the groundingy of 'start conductor 208, effected by the upper contacts of transfer relay TRI at the end of the transmission of the rst digit from the control station.

When, following transmission of the'preliminary digit blank, digit-control lead DCI is energized, marking potential is thereby extended through the closed pair of register contacts of the regi-ster RI to the concerned one of the mark leadsV MI to M5, thereby causing the impulse counter of Fig. 2 to transmit the rst digit of the recorded value. Similarly, when the` energizing potential is transferred from conductor DCI to DCZ, one or another of the mark'leads MI to M5 is energized depending lupon the setting of the register R2, causing the second transmitted digit to have a corresponding .`va1ue. Finally, when the energizing potential is transferred to digit control conductor DC3, rone or another of the mark lead-s MI to M5 is supplied with energizing potential according to the vsetting of the register R3, causing the third transmitted digit to have a value corresponding to such setting.

The fact that asecond digit has been recorded is indicated to the digit counter of Fig. 3 by theapplication of ground potential to locking conductor L3 at Ythe upper contacts of sound transfer relay TR2. The fact that a third digit has been recordedv is indicated to the digit counter Vof Fig. 3 by the grounding of locking conductor L3 at the olf-normal contacts of the register R3.v y

, HLM. CLEARING oUT When the recorded number has been'transmitted a desired number of times, the operator at control. station CSI may initiate the clearing- Y out operation by momentarily actuating the non- Y locking release key R2.

Operation of this key grounds conductor 301, thereby short-circuiting the upper winding of chain relay CI2. Relay CI2 thereuponA restores. At its upper contacts, relay VCIS ungrounds conductor 303, thereby preventing the transmission of a further impulse over conductor 302 upon the restoration of relay IMP, which occur-s responsive to the opening of the lower contacts of relay C I2.

Lamp 3I6 becomes extinguished responsive to the opening of the lower contacts of relay CI2, notifying the operator that the release key R2 may be restored. Upon the restoration of key R2, chain-control relay CC2 restores. At the lower contacts of relay CC2, the ground connection initially made to conductor 300 is'opened, leaving this conductor grounded, if at all, by way of start conductor 208. If start conductor 208v is grounded, a-s it is when the impulse-sending apparatus is in any position other than its digit-blank position, conductor 300 is thereby maintained grounded to hold relays TRI and TR2 operated, along with the registers RI to R3.

When the sending apparatus next reaches its digit-blank position, and start conductor 208 becomes ungrounded, conductor 300 i-s consequently responsive to the ungrounding of conductor 208,V

reapplies potential to guard conductor 201, and 

